Ketchups

Ketchup acts as a food preserve because of its high concentration of vinegar (acetic acid) and sugar, both of which prevent the growth of harmful bacteria. When making it, the combination of boiling, reducing volume, and adding these antimicrobial ingredients creates a highly shelf-stable condiment.

Historically, "ketchup" wasn't even made of tomatoes. Dating back to 17th-century Asia, it was a fermented fish or mushroom sauce used as a base for preserving other foods. When the recipe evolved in 19th-century America, cooks used the same preservation principles to extend the lifespan of seasonal garden tomatoes.

• Vinegar (Acetic Acid): The high acidity lowers the pH, creating an environment where foodborne pathogens and mold cannot thrive.

• Sugar & Salt: These ingredients bind to the available water (lowering "water activity"). This deprives microbes of the moisture they need to survive and multiply.

• Heat Processing: The cooking process and hot water bath eliminate existing bacteria, sterilizing the mixture before it is sealed in airtight jars.

Ketchup has come a long way from its origins as a fermented fish sauce in ancient Asia. The word "ketchup" likely derives from the Hokkien Chinese term kê-chiap or kôe-chiap, meaning the brine of pickled fish or shellfish. Through trade routes, the condiment spread across Southeast Asia, influencing the Malay kicap and eventually entering the English language in the late 17th century. Early British and American ketchups bore little resemblance to today's version, featuring ingredients such as mushrooms, oysters, walnuts, anchovies, grapes, and mussels.

🍄 In 18th-century Britain, mushroom ketchup became especially popular as a savory seasoning. The transition to tomato ketchup began in the United States, where a tomato-based recipe appeared in 1824 in The Virginia Housewife by Mary Randolph. By the mid-19th century, tomato ketchup had become increasingly popular, partly because consumers trusted cooked and highly seasoned tomatoes more than fresh ones.

🍅 Modern ketchup owes much of its development to science and food safety. In the early 1900s, concerns about chemical preservatives led manufacturers such as the H. J. Heinz Company to increase the amount of vinegar and sugar while using ripe, high-pectin tomatoes. Research by USDA scientist Katherine Bitting demonstrated that these changes naturally prevented spoilage, helping establish the thick, sweet-and-sour ketchup recognized worldwide today.

🧪 Ketchup is also scientifically fascinating. It is a non-Newtonian fluid, meaning its viscosity changes when force is applied. This is why ketchup stubbornly stays in the bottle until shaken or tapped, after which it suddenly flows. Its unique texture comes from a complex network of water, sugars, acids, and tomato pectin that forms a temporary gel-like structure.

🍽️ Today, ketchup is one of the world's most popular condiments, used far beyond burgers and fries. It serves as a base for countless sauces and dressings, flavors snack foods, and appears in cuisines around the globe. From fermented fish brine to a scientific marvel and culinary staple, ketchup's history reflects centuries of cultural exchange, innovation, and evolving tastes.

Ketchup or catsup is a table condiment with a sweet and sour flavor. "Ketchup" now typically refers to tomato ketchup, although early recipes for different varieties contained mushrooms, oysters, mussels, egg whites, grapes, or walnuts, among other ingredients.

Tomato ketchup is made from tomatoes, sugar, and vinegar, with seasonings and spices. The spices and flavors vary but commonly include onions, allspice, coriander, cloves, cumin, garlic, mustard and sometimes include celery, cinnamon, or ginger. Tomato ketchup is sometimes used as a condiment for dishes that are usually served hot, and are fried or greasy.

Tomato ketchup is sometimes used in other sauces and dressings, such as Thousand Island dressing and Marie Rose sauce, or as a general cooking ingredient. Its flavor may be replicated as an additive flavoring for snacks, such as potato chips.

The term used for the sauce varies. Ketchup is the dominant term in North America and the UK, though catsup is commonly used in some southern US states and Mexico. The term "tomato sauce" is also used in the UK for something similar.

A folk etymology is that the word came from the Amoy (Xiamen) region of China into English, as a borrowed word 茄汁 (Cantonese, meaning "tomato sauce"; the character 茄 means 'eggplant'; tomato in Chinese is 番茄, so the phrase translates to foreign eggplant sauce).

Another theory is that the word derives from one of two words from Hokkien of the Fujian region of coastal southern China: kôe-chiap (in the Amoy / Xiamen dialect and Quanzhou dialect) or kê-chiap (in the Zhangzhou dialect). Both pronunciations of the same word (膎汁, kôe-chiap / kê-chiap) come from the Quanzhou dialect, Amoy dialect, and Zhangzhou dialect of Hokkien, respectively, where it meant the brine of pickled fish or shellfish (膎, 'pickled food' (usually seafood) + 汁, 'juice'). There are citations of koe-chiap in the Chinese-English Dictionary of the Vernacular or Spoken Language of Amoy (1873) by Carstairs Douglas, defined as "brine of pickled fish or shell-fish".

Ketchup may have entered the English language from the Malay word kicap. Originally meaning "soy sauce", the word itself derives from Chinese. In Indonesian cuisine, which is similar to Malay, the term kecap refers to fermented savory sauces. Two main types are well known in their cuisine: kecap asin, which translates to "salty kecap" in Indonesian (a salty soy sauce) and kecap manis or "sweet kecap" in Indonesian. Kecap manis is a sweet soy sauce that is a mixture of soy sauce with brown sugar, molasses, garlic, ginger, anise, coriander and a bay leaf reduced over medium heat until rather syrupy. A third type, kecap ikan, meaning "fish kecap" is fish sauce similar to the Thai nam pla or the Philippine patis. It is not, however, soy-based.

American anthropologist E. N. Anderson relies on Elizabeth David to claim that ketchup is a cognate of the French escavèche, meaning "food in sauce". The word also exists in Spanish and Portuguese forms as escabeche, "a sauce for pickling", which culinary historian Karen Hess traced back to Arabic kabees, or "pickling with vinegar". The term was anglicized to caveach, a word first attested in the late 17th century, at the same time as ketchup.

The term ketchup first appeared in 1682. The word entered the English language in Britain during the late 17th century, appearing in print as ketchup (1682), catchup (1690), and later as catsup (1730). Recipes for many types of ketchup began to appear in British and then American cookbooks in the 18th century. In the United Kingdom, from the 1600s ketchup was prepared with mushrooms as a primary ingredient, rather than tomatoes. In the United States, mushroom ketchup dates back to at least 1770, and was prepared by British colonists in the Thirteen Colonies.

In 1824, a ketchup recipe using tomatoes appeared in The Virginia Housewife (an influential 19th-century cookbook written by Mary Randolph, Thomas Jefferson's cousin). Tomato ketchup was sold locally by farmers. Jonas Yerkes is credited as the first American to sell it in a bottle. By 1837, he had produced and distributed the condiment nationally. By the mid-1850s, anchovies no longer featured as an ingredient. Shortly thereafter, other companies followed suit. By 1897, the Sears catalog reported "there are hundreds of brands of Catsup on the market, a few of them good."

American cooks also began to sweeten ketchup in the 19th century. The Webster's Dictionary of 1913 defined "catsup" as: "table sauce made from mushrooms, tomatoes, walnuts, etc. [Also written as ketchup]." As the century progressed, tomato ketchup began to gain popularity in the United States. Tomato ketchup was popular long before fresh tomatoes were. People were less hesitant to eat tomatoes as part of a highly processed product that had been cooked and infused with vinegar and spices.

With industrial ketchup production and a need for better preservation, there was a great increase of sugar in ketchup, leading to the typically sweet and sour formula of today. In Australia, it was not until the late 19th century that sugar was added to tomato sauce, initially in small quantities, but today it contains just as much as American ketchup and only differed in the proportions of tomatoes, salt and vinegar in early recipes. While ketchup and tomato sauce are both sold in Australia, American ketchup is sweeter and thicker, whereas Australian tomato sauce is sourer and runnier.

Modern ketchup emerged in the early years of the 20th century, out of a debate over the use of sodium benzoate as a preservative in condiments. Harvey W. Wiley, the "father" of the US Food and Drug Administration, challenged the safety of benzoate which was banned in the 1906 Pure Food and Drug Act. In response, entrepreneurs including Henry J. Heinz, pursued an alternative recipe that eliminated the need for that preservative. Katherine Bitting, a bacteriologist working for the U.S. Department of Agriculture, carried out research in 1909 that proved increasing the sugar and vinegar content of the product would prevent spoilage without use of artificial preservatives. She was assisted by Arvil Bitting, her husband and an official at that agency.

Prior to Heinz, commercial tomato ketchups of that time were watery and thin, in part because they used unripe tomatoes, which were low in pectin. They had less vinegar than modern ketchups; by pickling ripe tomatoes, the need for benzoate was eliminated without spoilage or degradation in flavor. The changes driven by the desire to eliminate benzoate also produced changes that some experts (such as Andrew F. Smith) believe were key to the establishment of tomato ketchup as the dominant American condiment.

In fast food outlets, ketchup is often dispensed in small sachets or tubs. Diners tear the side or top of ketchup packets and squeeze ketchup out of them or peel the foil lid off tubs for dipping. Some fast food outlets previously dispensed ketchup from hand-operated pumps into paper cups. This method has made a comeback in the first decades of the 21st century, as cost and environmental concerns over the increasing use of individual plastic ketchup tubs were taken into account.

Some ketchup in the U.S. is labeled "Fancy," a USDA grade related to relative density (also known as specific gravity). Fancy ketchup has a higher tomato solid concentration than other USDA grades.

Grade  Specific gravity          Total solids

Fancy   1.15  33%

Extra Standard 1.13  29%

Standard       1.11  25%

Ketchup is a non-Newtonian fluid, meaning that its viscosity changes under stress and is not constant. It is a shear thinning fluid, which means its viscosity decreases with increased shear stress. Viscosity is dependent on stress. This is apparent when one shakes a bottle of ketchup so it becomes liquid enough to squirt out. Its viscosity decreases with stress.

The molecular composition of ketchup is what creates its pseudoplastic characteristics. Small polysaccharides, sugars, acids, and water make up the majority of the metastable ketchup product, and these small structures are able to move more easily throughout a matrix because of their low mass. While exposed to shear stress, the molecules within the suspension are able to respond quickly and create an alignment within the product. The bonds between the molecules are mostly hydrogen bonds, ionic interactions, and electrostatic interactions, all of which can be broken when subject to stress. Hydrogen bonds are constantly rearranging within a product due to their need to be in the lowest energy state, which further confirms that the bonds between the molecules will be easily disrupted. This alignment only lasts for as long as shear stress is applied. The molecules return to their original disorganized state once the shear stress dissipates.

Ketchup is one of the many products that are leachable, meaning that the water within the product migrates together as the larger molecules within the product sediment, ultimately causing water to separate out. This forms a layer of water on top of the ketchup due to the molecular instability within the product. This instability is caused by interactions between hydrophobic molecules and charged molecules within the ketchup suspension.

Pectin is a polysaccharide within tomatoes that has the ability to bind to itself and to other molecules, especially water, around it. This enables it to create a gel-like matrix, dependent on the amount within the solution. Water is a large part of ketchup, due to it being 80% of the composition of distilled vinegar. In order for the water within the ketchup to be at the lowest possible energy state, all of the hydrogen bonds that are able to be made within the matrix must be made. The water bound to the polysaccharide moves more slowly within the matrix, which is unfavorable with respect to entropy. The increased order within the polysaccharide-water complex gives rise to a high-energy state, in which the water will want to be relieved. This concept implies that water will more favorably bind with itself because of the increased disorder between water molecules. This is partially the cause for water leaching out of solution when left undisturbed for a short period of time.

Ketchup has one of the most surprising histories in food, it did not begin as a tomato condiment at all. Its evolution spans Southeast Asia, China, colonial trade routes, and finally industrialized Western cuisine.

17th century origins: Southeast Asian fish sauces

The earliest ancestor of ketchup comes from Southeast Asia, especially regions that are now part of Malaysia and Indonesia.

There, traders encountered fermented sauces called:

• kecap (Indonesian word meaning “sauce” or “to ferment”)

• Made from fish, salt, and spices

• Often dark, salty, and umami-rich

British and Dutch traders encountered these sauces during colonial trade in the 1600s and brought the concept back to Europe. Early “ketchup” was a category of exotic sauces.

18th century: ketchup becomes a British “sauce idea”

By the 1700s in Britain:

• “Ketchup” referred to a wide range of savory sauces

• Recipes were experimental and highly varied

• Ingredients included anchovies and even beer

Examples of early British ketchups:

• Mushroom ketchup (one of the most popular)

• Walnut ketchup

• Oyster ketchup

These were:

• Thin, dark sauces

• Used to flavor meats, stews, and soups

• Closely related to Worcestershire-style sauces

At this stage, ketchup had no tomatoes in it at all.

Early 19th century: introduction of tomato ketchup

Tomatoes began entering ketchup recipes in the early 1800s in the United States.

Key developments:

• Tomatoes were initially considered suspicious or ornamental in some regions

• By the early 1800s, cooks began making tomato-based ketchups as one variation among many

• Early tomato ketchup was often thin, spicy, and sometimes alcoholic (vinegar or wine-based preservation)

One of the first published tomato ketchup recipes appeared in the U.S. in the early 19th century.

Mid–late 19th century: industrialization and standardization

This is when ketchup becomes the product we recognize today.

• Commercial production begins in the U.S.

• Vinegar becomes the main preservative (instead of fermentation or alcohol)

• Sugar is added to balance acidity

• Recipes are standardized for consistency and shelf stability

By the late 1800s:

• Tomato ketchup had overtaken other versions in popularity

• “Ketchup” in the U.S. increasingly meant tomato ketchup specifically

Glass bottles and industrial bottling made ketchup a mass-market product.

Early 20th century: global dominance of tomato ketchup

In the 1900s:

• Tomato ketchup became a global condiment staple

• Brands like Heinz standardized smooth texture and sweet-tangy flavor

• Refrigeration and pasteurization improved safety and shelf life

Ketchup became strongly associated with:

• Fast food culture

• French fries, burgers, hot dogs

• American cuisine exports worldwide

Other ketchups (mushroom, walnut, etc.) largely disappeared from mainstream markets.

Late 20th century: global adaptation and diversification

While tomato ketchup dominated, variations continued:

• Spicy ketchups in Latin America and Asia

• Fruit-based ketchups in some regions (banana ketchup in the Philippines is especially notable)

• Gourmet and artisanal ketchups using heirloom tomatoes or alternative sweeteners

Ketchup also became a global “base sauce” for fusion cuisine.

21st century: redefinition and culinary experimentation

Today, ketchup exists in multiple forms:

• Classic tomato ketchup (industrial standard)

• Organic, low-sugar, and artisanal versions

• Regional variants (banana ketchup, curry ketchup, etc.)

• Chef-driven reinterpretations using smoked tomatoes, spices, or fermentation

Modern culinary uses include:

• Dip for fried foods

• Ingredient in sauces, marinades, and glazes

• Flavor base in global fusion cooking

Ketchup began as a fermented fish sauce from Southeast Asia, became a flexible category of savory sauces in 18th-century Britain, and eventually transformed in 19th-century America into the tomato-based, sweet-tangy condiment now known worldwide.